// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_WEBSOCKETS_WEBSOCKET_EXTENSION_PARSER_H_
#define NET_WEBSOCKETS_WEBSOCKET_EXTENSION_PARSER_H_

#include <stddef.h>

#include <string>
#include <vector>

#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/strings/string_piece.h"
#include "net/base/net_export.h"
#include "net/websockets/websocket_extension.h"

namespace net {

class NET_EXPORT_PRIVATE WebSocketExtensionParser {
public:
    WebSocketExtensionParser();
    ~WebSocketExtensionParser();

    // Parses the given string as a Sec-WebSocket-Extensions header value.
    //
    // There must be no newline characters in the input. LWS-concatenation must
    // have already been done before calling this method.
    //
    // Returns true if the method was successful (no syntax error was found).
    bool Parse(const char* data, size_t size);
    bool Parse(const std::string& data)
    {
        return Parse(data.data(), data.size());
    }

    // Returns the result of the last Parse() method call.
    const std::vector<WebSocketExtension>& extensions() const
    {
        return extensions_;
    }

private:
    WARN_UNUSED_RESULT bool Consume(char c);
    WARN_UNUSED_RESULT bool ConsumeExtension(WebSocketExtension* extension);
    WARN_UNUSED_RESULT bool ConsumeExtensionParameter(
        WebSocketExtension::Parameter* parameter);
    WARN_UNUSED_RESULT bool ConsumeToken(base::StringPiece* token);
    WARN_UNUSED_RESULT bool ConsumeQuotedToken(std::string* token);
    void ConsumeSpaces();
    WARN_UNUSED_RESULT bool Lookahead(char c);
    WARN_UNUSED_RESULT bool ConsumeIfMatch(char c);
    size_t UnconsumedBytes() const { return end_ - current_; }

    static bool IsControl(char c);
    static bool IsSeparator(char c);

    // The current position in the input string.
    const char* current_;
    // The pointer of the end of the input string.
    const char* end_;
    std::vector<WebSocketExtension> extensions_;

    DISALLOW_COPY_AND_ASSIGN(WebSocketExtensionParser);
};

} // namespace net

#endif // NET_WEBSOCKETS_WEBSOCKET_EXTENSION_PARSER_H_
